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Old 08-16-2003, 05:17 PM
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Brent Mills Brent Mills is offline
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Join Date: Jan 1999
Location: Duvall, Wa
Cobra Make, Engine: KMP286, Shelby 482, Webers, 593HP
Posts: 4,162
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Default FE investigation continues. I welcome your input.

Many of you probably already know that I broke another push rod the other day in my new engine. Only common link between this engine and the last one is the rocker arms and the last engine broke push rods too. This engine is running a milder cam at about .540 lift and 240 duration, less spring pressure than the last, harland sharp rockers & hardened shafts, precision stands, supports, and spacers. Stock 427 type push rods.

Here's what I know and have done to this point:

1. #4 intake push rod broken

2. Removed the manifold and have found all of the big stuff. Took a magnet to every concievable spot to pick up any tiny stuff.

3. Inspected lifter and looks perfect.

4. Did an little leak down test without any sort of gauge. Took a compression tester end and mated a air hose to it and pushed about 100 psi into the cylinder. Wasn't sure what to expect, so tried all four on that side of the engine and they acted about the same. Loose very little to the valves, but most leaks past the rings (not certain if that's supposed to be the case, but it was at least consistent on the 4 I listened to. Engine has about 300 miles, so not sure if everything is fully seated?

5. Interestingly found no additional broken push rods, but these push rods have a grooved top edge of the cup (the top rim of the cup is like a "v" all the way around), but quite a few of them have the very outer edge of the groove is broken off (the outside edge of the v is broken off). I found a couple pieces in the head crevices that matched right up to the push rods. The thing is, I don't see how at any angle the edges would be hitting anything, but....Ideas?

Aside from questions above, are there any other things you would do at this point while I have crap apart? Anyone using Precision Oil Pums rockers? Any other suggestions on parts I should get?

I'm actually at least feeling like I'll be back on the road shortly...I hope.
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